Metamath Proof Explorer


Theorem wuntpos

Description: A weak universe is closed under transposition. (Contributed by Mario Carneiro, 12-Jan-2017)

Ref Expression
Hypotheses wun0.1 φ U WUni
wunop.2 φ A U
Assertion wuntpos φ tpos A U

Proof

Step Hyp Ref Expression
1 wun0.1 φ U WUni
2 wunop.2 φ A U
3 1 2 wundm φ dom A U
4 1 3 wuncnv φ dom A -1 U
5 1 wun0 φ U
6 1 5 wunsn φ U
7 1 4 6 wunun φ dom A -1 U
8 1 2 wunrn φ ran A U
9 1 7 8 wunxp φ dom A -1 × ran A U
10 tposssxp tpos A dom A -1 × ran A
11 10 a1i φ tpos A dom A -1 × ran A
12 1 9 11 wunss φ tpos A U